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Steve W.[_4_]

wrote:
On Jul 11, 3:57 pm, "Phil Kangas" wrote:
I'm involved with a repair project to restore an old
sickle bar hay mower that may be about 50 years
old. The manufacturer is unknown and there is no
parts manual either. The input shaft that connects
to the pto shaft has a 'dog clutch' (that's what I'm
calling it for lack of a better term) that is worn out.
The drive lugs are gone and someone in the past
welded the two parts of the clutch together! Not
good! So I made a replacement unit but I don't know
what the angles of the drive lugs should be. The two
halves are held in engagement by a heavy spring.
I can't find any info on the web about this unit so
I'm guessing for a start that the angle of contact is
45 deg simply because I had a cutter to do that.
Now it's back in service but it ratchets too easily
so maybe the contact angle is wrong? Anyone out
there in RCM know what I'm talking about? Perhaps
the angle should be only 30 deg.? This unit is 3 inches
in dia. with a 1.25" bore....
phil kangas

Phil, is the wooden pitman arm still on the mower? This is the
secondary safety point on old mowers. It will break if the slip clutch
doesn't slip. On old mowers, the wooden arm is usually rotten after
being outside in the weather for a few years. It may also have been
replaced by a steel arm.

Probably someone was mowing brush with the mower and jammed the cycle
bar one too many times and decided to fix it good and for ever!

I loved watching the cut grass fall behind the cycle bar until I ran
through a phesant's nest and cut the legs off the hen. Cats also were
a problem.

Paul

Yeah sickle bars are nice and quiet compared to most modern cutting
methods. The quiet part is what caused a lot of the problems. The
animals didn't hear you coming and didn't run. Of course I would rather
not hit a 'chuck hole while on a horse drawn unit though. Not much in
the way of suspension or comfort with steel wheels and a steel seat!!!

--
Steve W.
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